WR400 99 Carb slide failure

I am currently doing a full rebuild on my 99 WR400.

I have read that the slide in this years carb are prone to break and can cause major engine problems when they do.

How do I know if its ok? Can I buy an updated part that has been improved or do I need a new carby?

I dont want to buy a whole new carby but want to be sure its not going to fail. Would simply checking it for visalbe cracks every x hrs allow me to see it before its too late?

It's not the slide, it's the slide plate.

If you keep up with with replacing the slide plate seal, the slide plate never cracks.

If you don't, it will bounce around and eventually (hundreds of hours) crack.

If you ignore the crack, a piece can break off.

If you do yearly maintenece on  the carb, don't worry about it.


This is the case with all bikes that use this FCR Slant body carb.

After doing more research, the carb on my bike has the red hot start button.

Correct me if i am wrong but isnt this the FCR2 which does not have the slide issue?

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